The families of flowering plants
Including Nupharaceae Nak.; excluding Barclayaceae, Cabombaceae, Euryalaceae.
Habit and leaf form. Aquatic herbs; laticiferous. Perennial; rhizomatous. Hydrophytic; rooted. Leaves floating. Leaves medium-sized to large; alternate; spiral; petiolate; simple; usually more or less peltate. Lamina entire; usually more or less orbicular; basically palmately veined; cross-venulate; usually cordate. Leaves stipulate (the stipules median-axillary), or exstipulate; leaf development not graminaceous.
General anatomy. Plants with laticifers (these articulated). The laticifers in leaves, in stems, in roots, in flowers, and in the fruits.
Leaf anatomy. The leaf lamina dorsiventral. Stomata present; mainly confined to one surface (the upper surface); anomocytic. Hairs present; eglandular and glandular (the latter mucilaginous, with an enlarged terminal cell); multicellular. Multicellular hairs uniseriate; simple. The mesophyll with sclerenchymatous idioblasts (these branched). Foliar vessels absent. Minor leaf veins without phloem transfer cells (Nymphaea).
Axial (stem, wood) anatomy. Pith with diaphragms, or without diaphragms. Primary vascular tissues consisting of scattered bundles. Secondary thickening absent (the scattered vascular bundles closed, monocotyledon-like, lacking sclerenchyma). The axial xylem without vessels.
The axial xylem with tracheids (with spiral or annular thickenings).
Root anatomy. Root xylem without vessels.
Reproductive type, pollination. Plants hermaphrodite. Pollination entomophilous.
Inflorescence, floral, fruit and seed morphology. Flowers solitary; large; often fragrant; regular; partially acyclic. The perianth acyclic and the androecium acyclic. Free hypanthium absent.
Perianth with distinct calyx and corolla (e.g. Nymphaea, according to the usual interpretation), or petaline (Nuphar); 5, or 20–50 (many); free. Calyx as commonly interpreted 4, or 5; polysepalous; imbricate. Corolla 5 (Nuphar), or 15–50 (many, showy); polypetalous; imbricate.
Androecium 40–80. Androecial members maturing centripetally; free of the perianth; free of one another; spiralled. Androecium including staminodes (with transition from petals to stamens). Staminodes 11–20 (in the form of nectariferous scales, in Nuphar); external to the fertile stamens; in Nuphar, petaloid. Stamens 40–80; petaloid, or laminar, or filantherous (in sequence). Anthers adnate; non-versatile; dehiscing via longitudinal slits; introrse; locule number?; tetrasporangiate. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral. Anther wall initially with more than one middle layer. Tapetum glandular. Pollen shed as single grains. Pollen grains aperturate; 1 aperturate; sulcate, or zoniaperturate; 2-celled.
Gynoecium 5–35 carpelled. The pistil 5–35 celled. Gynoecium syncarpous; eu-syncarpous; superior to partly inferior. Ovary 5–35 locular. Placentation more or less parietal (or ovules more or less scattered). Ovules 10–100 per locule (i.e. many); arillate, or non-arillate; orthotropous, or anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type. Antipodal cells formed; 3; not proliferating; very ephemeral. Synergids pear-shaped. Endosperm formation cellular. Embryogeny asterad.
Fruit fleshy; dehiscent, or indehiscent, or a schizocarp (irregularly so, Nuphar). Mericarps in Nuphar, 5–35 (?). Fruit when non-schizocarpic, a berry; enclosed in the fleshy receptacle. Seeds endospermic. Perisperm present. Cotyledons 1, or 2. Embryo chlorophyllous (2/2); straight.
Seedling. Germination cryptocotylar.
Physiology, phytochemistry. C3. C3 physiology recorded directly in Nuphar. Anatomy non-C4 type (Brasenia, Nuphar, Nymphaea). Accumulated starch other than exclusively pteridophyte type. Not cyanogenic. Alkaloids present (usually), or absent. Iridoids not detected. Saponins/sapogenins absent. Proanthocyanidins present, or absent; cyanidin, or delphinidin. Flavonols present, or absent (Nuphar); in Nymphaea, kaempferol and quercetin, or myricetin. Ellagic acid present (one Nymphaea sample), or absent (Nymphaea capensis, Nuphar lutea). Aluminium accumulation not found. Sieve-tube plastids S-type.
Geography, cytology. Temperate to tropical. Cosmopolitan, except in frigid zones.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Nymphaeiflorae; Nymphaeales. Cronquists Subclass Magnoliidae; Nymphaeales. APG 3 peripheral angiosperms; Superorder Nymphaeanae; Order Nymphaeales.
Species 75. Genera 3; Nymphaea, Nuphar, Ondinea.
General remarks. The Metcalfe and Chalk (1965) account of Nymphaeaceae sensu lato employed here does not permit satisfactory anatomical treatment of the sensu stricto families.
The Water Lilies,
white and yellow flowers,
How beautiful they are upon the lake!
(John Clare 1841, The Water Lilies Nymphaea alba)
Illustrations. • Nymphaea: Lindley. • Le Maout and Decaisne: Nuphar, Nymphaea. • Nymphaea alba (B. Ent.). • Nymphaea alba: Eng. Bot. 53, 1863. • Nuphar lutea (B. Ent.). • Nuphar lutea and N. pumila: Eng. Bot. 54 and 56, 1863. • Nymphaea micrantha: Bot. Mag. 76 (1850). • Nymphaea odorata subsp. minor: Bot. Mag. 109 (1883). • Nymphaea marliacis: TS leaf showing spicular idioblasts, with anatomical details of Nelumbo (Nelumbonaceae) and Brasenia (Cabombaceae). Solereder, 1908. • Foliar clothing and mucilage hairs of Nuphar luteum and Nymphaea alba, with mucilage hairs of Cabomba and Brasenia (Cabombaceae). Solereder, 1908.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 9th January 2018. delta-intkey.com/angio’.